2. Distinguish,differentiate,discriminate suggest an attempt to analyze characteristic features or qualities of things. To distinguish is to recognize the characteristic features belonging to a thing: to distinguish a light cruiser from a heavy cruiser. To discriminate is to perceive the particular, nice, or exact differences between things, to determine wherein these differences consist, and to estimate their significance: to discriminate prejudiced from unprejudiced testimony. To differentiate is to point out exactly and in detail the differences between (usually) two things: The symptoms of both diseases are so similar that it is hard to differentiate one from another.

The suffix -ish is due to the influence of many verbs in which it is the equivalent of Old French -iss-, ultimately from Latin inchoative suffix -iscere (this is also the case in extinguish, admonish, and astonish). Related: Distinguishing. The earlier form of the verb was distinguen (mid-14c.).